export default class EventEmitter {
    listeners = []

    on(cb) {
      this.listeners.push(cb);
      return () => {
        const index = this.listeners.indexOf(cb);
        if (index !== -1) this.listeners.splice(index, 1);
      };
    }

    emit(data) {
      this.listeners.forEach(fn => fn(data));
    }
}
